Photocatalytic degradation of methylene blue dye using newly synthesized zirconia nanoparticles

Comparative investigation of structural properties and biological applications of chemical and biogenic synthesis of zirconium dioxide (ZrO2) nanoparticles using Passiflora edulis

Over the last decade, the environmental and wellness cost of antibiotic drug resistance to the societies have been astounding and require urgent attention Metal oxide nanomaterials have been achieved a pull-on deal with its entire applications in biological and photocatalytic applications. The present study conducts a comparative investigation on chemical and biogenic synthesis of zirconium dioxide (ZrO2) nanoparticles aimed at enhancing their efficacy in their applications. The plant extract of Passiflora edulis act as a reducing and capping properties offering a sustainable and eco-friendly alternative. ZrO2 nanoparticles have drawn a lot of scrutiny owing to their potential uses in numerous fields, including medicine and environmental remediation. Thereby produced ZrO2 nanoparticles were synthesized by employing sustainable techniques, and their successful production and their uses were confirmed by characterization by XRD, FTIR, UV-visible spectroscopy, SEM, EDAX, PL, TEM, XPS, TGA and Raman spectroscopy. The zirconia nanoparticles synthesized using chemical and green methods exhibited ultraviolet-visible (UV-Vis) absorption maxima at 221 and 224 nm, respectively, demonstrating their synthesis. X-ray diffraction research revealed that the nanoparticles possess a tetragonal shape, with mean particle sizes of 11 nm and 7 nm, respectively. The synthesized ZrO2 nanoparticles (ZrO2 and Ext-ZrO2) exhibited inhibitory effects against Gram-positive strains (Bacillus subtilis and Staphylococcus aureus) and Gram-negative germs (Escherichia coli and Pseudomonas aureus), with zones of inhibition measuring (12, 8 mm), (8, 11 mm), (12, 15 mm), and (7, 12 mm) correspondingly. The antitumor activity of ZrO2 and Ext-ZrO2 was assessed using human colon cancer cells (HT29). The MTT assay was employed to assess the cytotoxicity of ZrO2 nanospheres on the HT-29 cell line at various concentrations (7.5, 15.6, 31.2, 62.5, 125, 250, and 500 μg/ml). The HT29 cell line exhibits a reduction in cell viability from 96 % to 34 % when the concentration of ZrO2 nanoparticles escalates. The photocatalytic activity of ZrO2 and Ext-ZrO2 exhibited absorbance deterioration at around 445 nm, resulting in the discoloration of Rh B dye under UV light irradiation after 100 min, achieving maximal degradation rates of 96 % and 99 %, respectively. Consequently, the synthesized ZrO2 and Ext-ZrO2 may be utilized in antibiotic formulation, pharmaceutical sectors, and photocatalysts.

Eco-Friendly Synthesis of Zirconium Dioxide Nanoparticles from Toddalia asiatica: Applications in Dye Degradation, Antioxidant and Antibacterial Activity

Zirconium dioxide nanoparticles (ZrO2 NPs) have gained significant attention due to their excellent bioavailability, low toxicity, and diverse applications in the medical and industrial fields. In this study, ZrO2 NPs were synthesized using zirconyl oxychloride and the aqueous leaf extract of Toddalia asiatica as a stabilizing agent. Analytical techniques, including various spectroscopy methods and electron microscopy, confirmed the formation of aggregated spherical ZrO2 NPs, ranging from 15 to 30 nm in size, with mixed-phase structure composed of tetragonal and monoclinic structures. UV-visible spectroscopy showed a characteristic band at 281 nm with a bandgap energy of 3.7 eV, indicating effective stabilization by the phytochemicals in T. asiatica. EDX analysis revealed that the NPs contained 37.18 mol.% zirconium (Zr) and 62.82 mol.% oxygen. The ZrO2 NPs demonstrated remarkable photocatalytic activity, degrading over 95% of methylene blue dye after 3 h of sunlight exposure. Additionally, the ZrO2 NPs exhibited strong antibacterial effects, particularly against Gram-negative bacteria such as E. coli, and significant antioxidant activity, with low IC50 values for hydroxyl radical scavenging. In conclusion, the green synthesis of ZrO2 NPs using T. asiatica leaf extract is an effective, eco-friendly method that produces nanoparticles with remarkable antioxidant, antimicrobial, and photocatalytic properties, highlighting their potential for applications in water treatment, environmental remediation, and biomedicine.

Bio‐Fabricated Silver Nanoparticles for Catalytic Degradation of Toxic Dyes and Colorimetric Sensing of Hg2+

In the present study, silver nanoparticles were synthesized via green synthesis using fenugreek (Trigonella foenum‐graecum L.) seeds of variety HM 425. The AgNPs were characterized by using UV‐Visible spectroscopy, Particle size analyzer, Field emission scanning electron microscopy coupled to Energy dispersive X‐ray spectroscopy, XRD, High resolution transmission electron microscopy and Fourier Transform Infrared Spectroscopy. The AgNPs were spherical and had an average particle size of 28 nm. The reduction of cationic dyes Methylene blue, Rhodamine B, and an anionic azo dye Methyl Orange by Sodium borohydride was used as a model reaction to investigate the catalytic ability of AgNPs. The results demonstrated an efficient catalytic dye degradation of methylene blue (95.81 %, 25 min, 0.1737±0.01 min−1), Rhodamine B (90.23 %, 15 min, 0.1388±0.01 min−1) and methyl orange (83.63 %, 39 min, 0.0412±0.002 min−1). The synthesized AgNPs had an excellent detection limit of 12.50 μM for Hg2+, making them excellent solid bio‐based sensors for mercury sensing.

Photocatalytic Organic Contaminant Degradation of Green Synthesized ZrO2 NPs and Their Antibacterial Activities

The green synthesis of metal oxide nanoparticles is an efficient, simple, and chemical-free method of producing nanoparticles. The present work reports the synthesis of Murraya koenigii-mediated ZrO2 nanoparticles (ZrO2 NPs) and their applications as a photocatalyst and antibacterial agent. Capping and stabilization of metal oxide nanoparticles were achieved by using Murraya koenigii leaf extract. The optical, structural, and morphological valance of the ZrO2 NPs were characterized using UV-DRS, FTIR, XRD, and FESEM with EDX, TEM, and XPS. An XRD analysis determined that ZrO2 NPs have a monoclinic structure and a crystallite size of 24 nm. TEM and FESEM morphological images confirm the spherical nature of ZrO2 NPs, and their distributions on surfaces show lower agglomerations. ZrO2 NPs showed high optical absorbance in the UV region and a wide bandgap indicating surface oxygen vacancies and charge carriers. The presence of Zr and O elements and their O=Zr=O bonds was categorized using EDX and FTIR spectroscopy. The plant molecules’ interface, bonding, binding energy, and their existence on the surface of ZrO2 NPs were established from XPS analysis. The photocatalytic degradation of methylene blue using ZrO2 NPs was examined under visible light irradiation. The 94% degradation of toxic MB dye was achieved within 20 min. The antibacterial inhibition of ZrO2 NPs was tested against S. aureus and E. coli pathogens. Applications of bio-synthesized ZrO2 NPs including organic substance removal, pathogenic inhibitor development, catalysis, optical, and biomedical development were explored.

Antibacterial, Antioxidant, and Phytotoxic Potential of Phytosynthesized Silver Nanoparticles Using Elaeagnus umbellata Fruit Extract

Due to its eco-friendliness, cost-effectiveness, ability to be handled safely, and a wide variety of biological activities, the green plant-mediated synthesis of nanoparticles has become increasingly popular. The present work deals with the green synthesis and characterization of silver nanoparticles (AgNPs) using Elaeagnus umbellata (fruit) and the evaluation of its antibacterial, antioxidant, and phytotoxic activities. For the synthesis of AgNPs, fruit extract was treated with a 4 mM AgNO₃ solution at room temperature, and a color change was observed. In UV-Visible spectroscopy, an absorption peak formation at 456 nm was the sign that AgNPs were present in the reaction solution. Scanning electron microscopy and physicochemical X-ray diffraction were used to characterize AgNPs, which revealed that they were crystalline, spherical, and had an average size of 11.94 ± 7.325 nm. The synthesized AgNPs showed excellent antibacterial activity against Klebsiella pneumoniae (14 mm), Staphylococcus aureus (13.5 mm), Proteus mirabilis (13 mm), and Pseudomonas aeruginosa (12.5 mm), as well as considerable antioxidant activity against DPPH with 69% inhibition at an IC₅₀ value of 43.38 µg/mL. AgNPs also exhibited a concentration-dependent effect on rice plants. Root and shoot length were found to be positively impacted at all concentrations, i.e., 12.5 µg/mL, 25 µg/mL, 50 µg/mL, and 100 µg/mL. Among these concentrations, the 50 µg/mL concentration of AgNPs was found to be most effective. The plant biomass decreased at higher AgNP exposure levels (i.e., 100 µg/mL), whereas 50 µg/mL caused a significant increase in plant biomass as compared to the control. This study provides an eco-friendly method for the synthesis of AgNPs which can be used for their antibacterial and antioxidant activities and also as growth promoters of crop plants.